summaryrefslogtreecommitdiff
path: root/libraries/base/Data/Proxy.hs
Commit message (Collapse)AuthorAgeFilesLines
* Minor typo in docs for KProxyJoachim Breitner2019-01-231-1/+1
| | | | really minor, but it annoyed me when reading it :-)
* Doc-only fixesAlec Theriault2018-11-221-1/+1
| | | | | | * laws are capitalized definition lists, no emphasis on the labels * adds missing hyperlinks * fixes other misc. Haddock markup issues.
* Embrace -XTypeInType, add -XStarIsTypeVladislav Zavialov2018-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Implement the "Embrace Type :: Type" GHC proposal, .../ghc-proposals/blob/master/proposals/0020-no-type-in-type.rst GHC 8.0 included a major change to GHC's type system: the Type :: Type axiom. Though casual users were protected from this by hiding its features behind the -XTypeInType extension, all programs written in GHC 8+ have the axiom behind the scenes. In order to preserve backward compatibility, various legacy features were left unchanged. For example, with -XDataKinds but not -XTypeInType, GADTs could not be used in types. Now these restrictions are lifted and -XTypeInType becomes a redundant flag that will be eventually deprecated. * Incorporate the features currently in -XTypeInType into the -XPolyKinds and -XDataKinds extensions. * Introduce a new extension -XStarIsType to control how to parse * in code and whether to print it in error messages. Test Plan: Validate Reviewers: goldfire, hvr, bgamari, alanz, simonpj Reviewed By: goldfire, simonpj Subscribers: rwbarton, thomie, mpickering, carter GHC Trac Issues: #15195 Differential Revision: https://phabricator.haskell.org/D4748
* Add @since annotations for derived instances in baseChaitanya Koparkar2018-03-021-2/+2
| | | | | | | | | | | | | | Test Plan: ./validate Reviewers: hvr, goldfire, bgamari, RyanGlScott Reviewed By: RyanGlScott Subscribers: rwbarton, thomie, carter GHC Trac Issues: #11767 Differential Revision: https://phabricator.haskell.org/D4452
* Make Semigroup a superclass of Monoid (re #14191)Herbert Valerio Riedel2017-09-071-1/+6
| | | | | | | | | | | | | | | | | | | Unfortunately, this requires introducing a couple of .hs-boot files to break up import cycles (mostly to provide class & typenames in order to be able to write type signatures). This does not yet re-export `(<>)` from Prelude (while the class-name `Semigroup` is reexported); that will happen in a future commit. Test Plan: local ./validate passed Reviewers: ekmett, austin, bgamari, erikd, RyanGlScott Reviewed By: ekmett, RyanGlScott GHC Trac Issues: #14191 Differential Revision: https://phabricator.haskell.org/D3927
* Make the Read instance for Proxy (and friends) ignore precedenceRyan Scott2017-08-221-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The `Read` instance for `Proxy`, as well as a handful of other data types in `base` which only have a single constructor, are doing something skeevy: they're requiring that they be surrounded by parentheses if the parsing precedence is sufficiently high. This means that `"Thing (Proxy)"` would parse, but not `"Thing Proxy"`. But the latter really ought to parse, since there's no need to surround a single constructor with parentheses. Indeed, that's the output of `show (Thing Proxy)`, so the current `Read` instance for `Proxy` violates `read . show = id`. The simple solution is to change `readParen (d > 10)` to `readParen False` in the `Read` instance for `Proxy`. But given that a derived `Read` instance would essentially accomplish the same thing, but with even fewer characters, I've opted to just replace the hand-rolled `Read` instance with a derived one. Test Plan: make test TEST=T12874 Reviewers: ekmett, austin, hvr, goldfire, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie GHC Trac Issues: #12874 Differential Revision: https://phabricator.haskell.org/D3871
* Loads of doc(test)sDavid Luposchainsky2017-08-171-1/+38
|
* Generalizes the type of asProxyTypeOf (#12805)Dave Laing2017-01-261-1/+1
| | | | | | | | | | | | | | Test Plan: validate Reviewers: austin, hvr, bgamari, RyanGlScott, simonpj Reviewed By: RyanGlScott, simonpj Subscribers: simonpj, RyanGlScott, thomie Differential Revision: https://phabricator.haskell.org/D3017 GHC Trac Issues: #12805
* Add @since annotations to base instancesSeraphime Kirkovski2016-06-061-0/+12
| | | | | | | | | | | | | | | | | | Add @since annotations to instances in `base`. Test Plan: * ./validate # some commets shouldn't break the build * review the annotations for absurdities. Reviewers: ekmett, goldfire, RyanGlScott, austin, hvr, bgamari Reviewed By: RyanGlScott, hvr, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2277 GHC Trac Issues: #11767
* Replace hand-written Bounded instances with derived onesRyan Scott2016-06-041-5/+1
| | | | | | | | | | | | | | | | | Summary: The spiritual successor to D2291, since deriving `Bounded` instances in `GHC.Enum` wasn't possible prior to changes made in that Diff. This Diff finds every manually implemented `Bounded` instance in `base` that is completely equivalent to the derived instances, and replaces it. Reviewers: bgamari, goldfire, austin, hvr Reviewed By: austin, hvr Subscribers: thomie, rwbarton Differential Revision: https://phabricator.haskell.org/D2301
* Missing Proxy instances, make U1 instance more Proxy-likeRyanGlScott2016-02-291-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | This accomplishes three things: * Adds missing `Alternative`, `MonadPlus`, and `MonadZip` instances for `Proxy` * Adds a missing `MonadPlus` instance for `U1` * Changes several existing `U1` instances to use lazy pattern-matching, exactly how `Proxy` does it (in case we ever replace `U1` with `Proxy`). This is technically a breaking change (albeit an extremely minor one). Test Plan: ./validate Reviewers: austin, ekmett, hvr, bgamari Reviewed By: bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1962 GHC Trac Issues: #11650
* Allow CallStacks to be frozenEric Seidel2015-12-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces "freezing," an operation which prevents further locations from being appended to a CallStack. Library authors may want to prevent CallStacks from exposing implementation details, as a matter of hygiene. For example, in ``` head [] = error "head: empty list" ghci> head [] *** Exception: head: empty list CallStack (from implicit params): error, called at ... ``` including the call-site of `error` in `head` is not strictly necessary as the error message already specifies clearly where the error came from. So we add a function `freezeCallStack` that wraps an existing CallStack, preventing further call-sites from being pushed onto it. In other words, ``` pushCallStack callSite (freezeCallStack callStack) = freezeCallStack callStack ``` Now we can define `head` to not produce a CallStack at all ``` head [] = let ?callStack = freezeCallStack emptyCallStack in error "head: empty list" ghci> head [] *** Exception: head: empty list CallStack (from implicit params): error, called at ... ``` --- 1. We add the `freezeCallStack` and `emptyCallStack` and update the definition of `CallStack` to support this functionality. 2. We add `errorWithoutStackTrace`, a variant of `error` that does not produce a stack trace, using this feature. I think this is a sensible wrapper function to provide in case users want it. 3. We replace uses of `error` in base with `errorWithoutStackTrace`. The rationale is that base does not export any functions that use CallStacks (except for `error` and `undefined`) so there's no way for the stack traces (from Implicit CallStacks) to include user-defined functions. They'll only contain the call to `error` itself. As base already has a good habit of providing useful error messages that name the triggering function, the stack trace really just adds noise to the error. (I don't have a strong opinion on whether we should include this third commit, but the change was very mechanical so I thought I'd include it anyway in case there's interest) 4. Updates tests in `array` and `stm` submodules Test Plan: ./validate, new test is T11049 Reviewers: simonpj, nomeata, goldfire, austin, hvr, bgamari Reviewed By: simonpj Subscribers: thomie Projects: #ghc Differential Revision: https://phabricator.haskell.org/D1628 GHC Trac Issues: #11049
* base: MRP-refactoring of AMP instancesHerbert Valerio Riedel2015-10-121-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This refactors `(>>)`/`(*>)`/`return`/`pure` methods into normal form. The redundant explicit `return` method definitions are dropped altogether. The explicit `(>>) = (*>)` definitions can't be removed yet, as the default implementation of `(>>)` is still in terms of `(*>)` (even though that should have been changed according to the AMP but wasn't -- see note in GHC.Base for details why this had to be postponed) A nofib comparision shows this refactoring to result in minor runtime improvements (unless those are within normal measurement fluctuations): Program Size Allocs Runtime Elapsed TotalMem ------------------------------------------------------------------------- Min -0.0% -0.0% -1.6% -3.9% -1.1% Max -0.0% +0.0% +0.5% +0.5% 0.0% Geometric Mean -0.0% -0.0% -0.4% -0.5% -0.0% Full `nofib` report at https://phabricator.haskell.org/P68 Reviewers: quchen, alanz, austin, #core_libraries_committee, bgamari Reviewed By: bgamari Differential Revision: https://phabricator.haskell.org/D1316
* Convert `/Since: .../` to new `@since ...` syntaxHerbert Valerio Riedel2014-12-161-1/+1
| | | | | | Starting with Haddock 2.16 there's a new built-in support for since-annotations Note: This exposes a bug in the `@since` implementation (see e.g. `Data.Bits`)
* Be consistent with placement of Safe Haskell mode at top of fileDavid Terei2014-11-211-1/+2
|
* Comments only (instances for Proxy are lazy)Reid Barton2014-10-031-0/+4
|
* Make Applicative a superclass of MonadAustin Seipp2014-09-091-0/+11
| | | | | | | | | | | | | | | | | | | | | Summary: This includes pretty much all the changes needed to make `Applicative` a superclass of `Monad` finally. There's mostly reshuffling in the interests of avoid orphans and boot files, but luckily we can resolve all of them, pretty much. The only catch was that Alternative/MonadPlus also had to go into Prelude to avoid this. As a result, we must update the hsc2hs and haddock submodules. Signed-off-by: Austin Seipp <austin@well-typed.com> Test Plan: Build things, they might not explode horribly. Reviewers: hvr, simonmar Subscribers: simonmar Differential Revision: https://phabricator.haskell.org/D13
* Add some instances for Monoid/Applicative (#8797)Austin Seipp2014-02-281-10/+0
| | | | | | | | | | | | | | | | | | | As noted in the ticket, there's no particular reason why there aren't Generic, Typeable, and Data instances for the types in the Monoid/Applicative modules. Furthermore, Product and Sum should also have Num instances as well as Edward noted. Aside from that, this patch also changes the dependency chain slightly - it moves the Monoid Proxy instance into Data.Monoid and out of Data.Proxy. Why? Cycles (of course). Monoid depends on Typeable. Typeable uses Proxy. Proxy uses Monoid. Boom. Luckily, Proxy only depends on Monoid outside of the GHC namespace, so the fix is easy and clean. Signed-off-by: Austin Seipp <austin@well-typed.com>
* Add Haddock `/Since: 4.7.0.0/` comments to new symbolsHerbert Valerio Riedel2013-09-211-0/+1
| | | | | | | | | | | | | | | | | | These annotations were added in such a way, that the line {{{ /Since: 4.7.0.0/ }}} represents the last paragraph of the Haddock comment. Maybe Haddock will have support for this meta-syntax at some point, and be able to inherited the since-version property to the children of an annotated symbol and display the since-version property in the rendered documentation only in cases when it's not visually obvious (for instance, when re-exporting documentation strings). Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
* Constant-fold `__GLASGOW_HASKELL__` CPP conditionalsHerbert Valerio Riedel2013-09-171-9/+1
| | | | | | | | | | Now that HUGS and NHC specific code has been removed, this commit "folds" the now redundant `#if((n)def)`s containing `__GLASGOW_HASKELL__`. This renders `base` officially GHC only. This commit also removes redundant `{-# LANGUAGE CPP #-}`. Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
* Add asProxyTypeOf and Trustworthy pragma to Data.ProxyRichard Eisenberg2013-07-311-2/+10
|
* Eliminate Equality.hs-boot and Proxy.hs-boot by moving instancesRichard Eisenberg2013-07-251-55/+23
|
* Implement "TypeLevelReasoning" proposal at wiki:TypeLevelReasoningRichard Eisenberg2013-07-241-0/+129
This commit includes a propositional equality (:=:) in Data.Type.Equality, a Proxy type in Data.Proxy, and has updates to Typeable. There is an unfortunate number of hs-boot files necessary, but that seems cleaner than moving Typeable instances around willy-nilly.
View Lorry Controller Status